Speed Training For Marathoners

The case for speed work for long distance runners

Sometimes it seems as though there are nearly as many marathon training programs as races. But if your marathon times have plateaued–or simply don't live up to what you think you might be capable of doing–it might be time to take a hard look at your own plan and see if it has enough speed work. Many plans focus on quantity of training, rather than quality, months of buildup with weekly long runs and grueling high-volume weeks. Such training, however, crowds out other forms of training that might give you more bang for your training effort. There's general agreement among scientists and coaches that running fast in training can improve our oxygen processing and help us run more economically–and therefore faster–in the marathon.

STILL RUNNING LONG

This doesn't mean you should ditch all of your prior training. "If you have to choose between intervals or long runs, I'd say long runs are better," says Tom McGlynn, founder of runcoach, an online training program.

But there's no reason to do long runs every week, says Owen Anderson, elite coach and exercise physiologist, in his new book, Running Science. Instead, he argues, weekly long runs increase injury risk and leave you too tired for high-quality workouts during the rest of the week. "Implicit in the philosophy of the long run is the suggestion that the human body will somehow forget how to go long . . . unless a weekly battering is administered to the leg muscles," he writes. "Nothing could be further from the truth!"

Overreliance on the long run may stem in part from a misguided effort to emulate the elites without realizing the difference between our long runs and theirs. For an elite running 140 miles a week, 20 miles is an average day, and doing 20 moderately paced ones in a single run may not be as big a shock to the legs for them as for us. (In fact, Joan Benoit Samuelson once used the phrase "20-mile recovery run" to describe some of her training runs at the peak of her career.)

But for those of us on lower mileage, Anderson suggests that we might do better to cut out half of the super-long runs and focus more on speed.

UPPING THE OXYGEN

One part of the speed formula is lactate threshold. (See "Find Your Tempo".) But another ingredient is more intense speed work built around a variable known as VO2 max.

VO2 max is a laboratory measure of the maximum amount of oxygen your body can process at peak effort. In other words, it's a measure of the power of your aerobic engine with all the parts–heart, lungs, capillaries and muscles–working at aerobic maximum. VO2 max is important because it's been long-known that there's a rough correlation between it and racing performance. A 3:20 marathoner, for example, might have a VO2 max of 45 to 50. In 2006, Ryan Hall in his prime tested at 78. That means that if you're a 3:20 marathoner, you might, in theory, be able to close up to one-sixth of the gap between you and Hall–a whopping 12 to 13 minutes–by adding a mere 5 points to your VO2 max.

But like many things at the intersection between exercise physiology and training, it's not that simple. Yes, you can indeed improve your VO2 max. But probably not by as much as you'd like. VO2 max is developed through years of training at high intensities (with possible assists from altitude training, altitude tents and heat training). In a 1978 study in the European Journal of Applied Physiology, a team led by Jack Daniels, author of Daniels' Running Formula, found that the average runner can increase it by only 5 percent to 15 percent–depressing news for most of those trying to turn a 4-hour marathon into a Boston qualifier.

Also, there comes a level at which experienced runners have probably already made the bulk of their potential gains. For example, after tracking 33 elite Spanish runners through four years of intense training, a 2005 study in the Journal of Sports Medicine and Physical Fitness led by Alejandro Legaz-Arrese of the University of Saragossa, Spain, found the runners' VO2 max levels to be essentially unchanged.

"In a nutshell, VO2 max reaches a plateau if you train hard," says John Halliwill, an exercise physiologist at the University of Oregon.

That said, many of us may not have trained hard enough to have hit the plateau encountered by Legaz-Arrese's Spanish runners. "People in very intense training programs, working daily with a coach, are pushing themselves to the point where they're probably not going to make changes in VO2 max," Halliwill says. "But others may have reached a temporary plateau, [and] if they did a more aggressive program they might see additional gains." Thus, it is worth spending time, even in marathon training, pushing this variable.

VELOCITY AT MAX

Even if your VO2 max has plateaued, though, there's another piece to the puzzle, called vVO2 max.

This is the pace you're running when your body first hits VO2 max. (The extra v means velocity.) It's by no means your top pace, but aerobically, you're maxed out. Anderson estimates it's about the pace you can maintain in a 6- to 10-minute time trial–somewhere between 1500m and 3K race pace, for most of us. A 6-minute all-out time trial, in fact, is a good way of estimating it.

Several factors other than VO2 max help determine vVO2 max, mostly related to running economy–the body's ability to make the best of the aerobic power nature and years of training have given it. And becoming more economical is where this 6-minute pace relates to a 3- to 4-hour race.

Halliwill suggests that the forward propulsion we get from any given amount of energy might be malleable, perhaps physiologically or perhaps simply by the effect of training on what Halliwill calls "the economy of how we move–whether we're wasting a lot of energy or doing it in the most economical way."

McGlynn adds that speed training also forces the body to learn to make use of "higher" energy systems not taxed during slower workouts. "The benefit is that you develop energy systems that utilize higher rates of glycogen and less fat than marathon pace," he says. "As you become more economical at faster paces, in theory you should become more economical with fat utilization at the slower pace, the marathon pace." He also notes that such training helps the body deal with glycogen depletion late in the marathon.

Veronique Billat, an exercise physiologist at the University of Lille, France, sees yet another speed-training advantage from improvements in your legs' "elastic energy reinstitution"–basically the rebound you get from stretched muscles as you launch from one stride into the next.